Why is my donut so grainy (cycles rendering)?
The noise or grain, in the image, is a can be decreased by two means.
First: increasing the samples
The &quot;Render and Viewport value&quot; is in fact the number of samples that Cycles are going to perform. The viewport refers to how many samples are done in the viewport rendering, and render refers to how many samples are done when actually rendering the final image.It could be that you increase the viewport samples and didn't increase the render.
In general the more samples the better, but you also have diminishing returns, for example, the difference between 10 and 100 samples is a lot, but between 100 and 200 not that much by comparison. also the more samples the longer the render is going to be.
Second: Denoising
In this method, you do a moderate amount of samples and add a denoiser after the render. There a couple of ways you can do this in Blender.

the first way can read more here
and here you can check another way
to denoise

the second way of denoising requires compositing in Blender, so if you are just beginning it may seem to complicate, so you may want to use the first denoising method.
as for the question &quot;Is this the best I can expect with my GPU?&quot; you are not technically limited to a certain quality by hardware, it just means you are going to have to wait for more for the same quality, but if you have the time you can do it. a GTX 1650 is pretty good.
hope this helps, good luck with blender :)